In conventional rotary electric machines, an armature core is configured by linking into an annular shape a plurality of core segments that have an approximate T shape that has a back yoke portion and a magnetic pole tooth portion that protrudes from the back yoke portion. Each of the core segments is configured by laminating a plurality of approximately T-shaped core pieces. When manufacturing armature cores, materials yield has been improved by arranging the core pieces in a staggered pattern such that the magnetic pole tooth portions of first core pieces are positioned between magnetic pole tooth portions of second core pieces and punching out two straight rows together (see Patent Literature 1, for example).
In other conventional rotary electric machines, an annular yoke is constituted by a plurality of laminated approximately T-shaped yoke pieces that are mutually rotatable, teeth are formed on the respective yoke pieces, and in the plurality of teeth, some gaps that are respectively formed between adjacent teeth are configured so as to be expandable in comparison with others. Winding of windings is facilitated, and loosening is also prevented from arising in crossover wires by deforming the annular yoke into a non-circular shape during the winding of the windings to expand some of the gaps that are respectively formed between adjacent teeth in comparison with others, and then winding the windings onto the teeth through the expanded gaps (see Patent Literature 2, for example).